Question: How do we approach the usage of the “X” placeholder character in ICD-10?
Michigan Subscriber
Answer: Remember that not all ICD-10 codes have an alphanumeric character for every place in the code, but may require a seventh character. In fact, there are codes that do not have a fourth, fifth, or perhaps even a sixth place, yet they require a seventh character. To address this we use a place holder character “X” to fill up the gap to the seventh character. Codes can even start with an X (i.e., X00-X009).
The location of the X is very important. If the “X” place holder is used as fourth, fifth, or sixth character it needs to be lower case. If it is used at the beginning of a code, it must be uppercase indicating the chapter.
ICD-10 guidelines regarding place holder characters state that the ICD-10-CM utilizes a placeholder character “X” at certain codes to allow for future expansion. You’ll find an example of this with the neck sprain codes under category S13.
Where a placeholder exists, the “X” must be used in the proper code position in order for the code to be considered a valid code.
Take note: Practice management software or electronic health records might already include the “X” placeholder when listing the code. That is not the case, however, when you look up the diagnosis in the book version of the ICD-10 code set. Here are a few examples of diagnoses that utilize the “X” placeholder: